dumb blade tip speed question

Discussion in 'Lawn Mowing' started by milo, Jul 4, 2008.

  1. GravelyNut

    GravelyNut LawnSite Bronze Member
    Messages: 1,593

    Actually they do get up to 60 RPS. Most small mower engines produce their rated HP at 3600 RPM.
     
  2. Richard Martin

    Richard Martin LawnSite Fanatic
    Messages: 14,697

    No, it's not. Tip speed is regulated by manufacturer insurance companies. Dixie Chopper mowers have been running tip speeds well in excess of 19,000 FPM for years on end.

    Please provide a direct link to this "law".
     
  3. Richard Martin

    Richard Martin LawnSite Fanatic
    Messages: 14,697

    There's a little weird math going on here....

    Why are you mutiplying the engine RPM by that pulley size? If the pulley is attached to the engine shaft then it's RPM will be the same as the engine's RPM.
     
  4. Happy Frog

    Happy Frog LawnSite Bronze Member
    Messages: 1,224

    If one pulley is involved in then two pulleys are involved (at least). Your calculation can't be right...
    Unless both pulleys are of the same size (then no pulley is involved)... :laugh::laugh::laugh:
     
  5. Phil G

    Phil G LawnSite Senior Member
    Messages: 844

    Blade tip speed 200mph:)











    =
     
  6. Genlandscape

    Genlandscape LawnSite Member
    Messages: 185

    I think Phil has put this in perspective. Your avg. comm. mower blade speed is between 170 and 215 mph. 16-19,000fpm If you guys have the time to do the math you must need more lawns to mow=:) and yes 50 revs. per second IS possible. Indy car engines turn in excess of 16,000 rpm, and I have a buddy who races karts and has briggs engines that turn in excess of 10,000rpm. I want one for my eXmark but he doesnt reccomend it LOL!! Imagine the blade tip speed on that puppy!!
     
  7. mtcjb

    mtcjb LawnSite Member
    Messages: 37


    that would scare the grass to the desired height lol
     
  8. OP
    OP
    milo

    milo LawnSite Bronze Member
    Messages: 1,357

    indy cars turn more like 18000 to 19000 rpm's formula one cars turn up to like 24000rpm's and thats just sick lol
     
  9. OldLawnMowerMan81

    OldLawnMowerMan81 LawnSite Member
    Messages: 66

    Would it be more appropriate if I said what the spindle pulley diameter and RPM should be? It's the kind of information you don't see very often are what the spindle pulley speed and diameter should be.
     
  10. ALC-GregH

    ALC-GregH LawnSite Fanatic
    from PA
    Messages: 7,051

    My friend in NY has a 19ft speed boat that idles at 24,000!!! It will spin in upwards of 56,000rpm. Talk about sick. :D He put a T63-A700 in the boat. ;) :D
     

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